为提供煤尘爆炸事故预防和缓解所需的科学依据,对煤尘爆炸火焰传播过程进行试验研究。所用试验装置,其主要部分为直径0.3 m的圆形管道与断面边长为80 mm的方形管道对接形成的一个长2 m的爆炸腔体。在其中共进行9次煤尘爆炸试验。结果表明,煤尘爆炸火焰传播具有速度快,波动大,稳定性较差的特点,火焰区长度远大于扬尘区长度,最大火焰速度和传播距离与煤尘量均不存在正比例关系,但存在一个特定的煤尘质量浓度。在这个特定质量浓度处,最大火焰速度达到最大值。当煤尘质量浓度大于这个特定质量浓度时,火焰传播速度曲线整体下降,暂时缺氧被认为是导致这一情况的重要因素。
For the sake of providing scientific basis for he coal dust explosion prevention and mitigation,spread of coal dust explosion flame was studied experimentally in the laboratory.The explosion cavity,a main part of the experimental system,is made of circular pipe of 0.3 m diameter and square pipes of 80 mm section side.9 coal dust explosion experiments were carried out.The results show that the flame propagation in coal dust explosion is fast,there are wild fluctuations in the flame,the flame area length is much greater than that of the dust area,neither the maximum flame speed nor the spread distance is proportionate to the amount of coal dust.However,there is a specific coal dust mass concentration,with which the flame speed can reach its maximum.When the coal dust mass concentration is higher than the specific one,the flame speed curve will overall decline.Temporary hypoxia is a very important factor behind this phenomenon.